With the rapid development of mobile devices, an application program has an urgent requirement for acquiring an instant message. An MBB device is a device that can provide a wireless network access service for a mobile device. A polling manner is mainly used currently to instantly acquire a message from the MBB device, that is, the mobile device periodically queries the MBB device, to confirm whether there is an instant message to be sent to an application program of the mobile device. According to permission settings of the MBB device, the MBB device has no capability of actively sending a notification message to a host, and also has no capability of waking up a host in a sleep state.
Therefore, the foregoing polling manner leads to a large quantity of signaling overheads between devices, and causes a mobile device to fail to sleep or fail to receive an instant message during sleep. Therefore, people expect a method for actively sending a message such that signaling overheads between devices can be reduced, and power consumption of a mobile device can be reduced.